Problems getting car to warm up when idle

I was just wondering if anyone has had problems with their Chryslers not heating up when idle. The heat on my 2002 Sebring just doesn't
seem to kick in until I start driving. Once I am on the go it heats up
in no time (whether I let the car warm up first or not.)

When I got my car last year I brought it back to the dealership about 4 times to look at it and pretty much told me there was nothing wrong. At one point they did change the thermostat, but that didn't do any good.

I am not a car savvy person, so I was hoping someone here may have an idea of what could be wrong.

Also, could anyone suggests a good Chrysler dealership/shop in the Mass Rt 128 area?

Thanks in advance!!

i would check the thermostat yourself
we had a similar problem w/ 97 breeze
would barely warm up at all
sitting or driving
the dealer said they changed the thermostat but when we checked it out the thermostat was in like 5 peices
the spring and the bottom parts were just sitting in the intake
most interesting thing ive ever seen

Same problem with my '97 Gr Voyager. Found the thermostat coming apart. Replaced and all better.